(07/18/2001) -- STS-105 Mission Specialist Patrick Forrester waits to don his helmet during suit fit check as part of Terminal Countdown Demonstration Test activities. He and other crew members Commander Scott Horowitz, Pilot Rick Sturckow and Mission Specialist Daniel Barry are also taking part in the TCDT, which includes emergency egress training and a simulated launch countdown. Mission STS-105 will be transporting the Expedition Three crew – Commander Frank Culbertson and Vladimir Nikolaevich Dezhurov and Mikhail Tyurin, both with the Russian Aviation and Space Agency – several payloads and scientific experiments to the International Space Station aboard Space Shuttle Discovery. The current Expedition Two crew members on the Station will return to Earth on Discovery. Launch of Discovery is scheduled no earlier than Aug. 9, 2001